Diabetes is one of the leading causes of morbidity and mortality in the United States. The cost for treating this disease in the United States is estimated to be about 98 billion dollars annually. The two most common forms of diabetes are referred to as type I and type II diabetes. Type I and type II diabetes are distinguished in that subjects with the type II form have normal or near normal levels of insulin, while subjects with type I have little or no insulin. Type I diabetes is therefore often referred to as insulin dependent diabetes.
Type I diabetes is characterized by an autoimmune reaction which destroys insulin-producing pancreatic beta (i.e., islet) cells. The proliferative capacity of adult pancreatic islet cells is limited. Pancreatic islet cell replacement represents one approach in the treatment of type I and insulin-requiring type II diabetes. This prospect of treatment, however, is restricted by the limited availability of donor cells. In addition to the lack of available donor tissue, immune-system mediated rejection of the transplanted tissue is another major impediment to widespread implementation of transplant therapy. The induction of islet cell neogenesis in the adult pancreas would be an important modality for the treatment of diabetes.